Axially arranged rotary threshing or separating systems have long been in use in agricultural combines for threshing crops to separate grain from crop residue, also referred to as material other than grain (MOG). Such axially arranged systems typically include at least one cylindrical rotor rotated within a concave or cage, the rotor and surrounding concave being oriented so as to extend forwardly to rearwardly within the combine.
In operation, crop material is fed or directed into a circumferential passage between the rotor and the concave, hereinafter referred to as a rotor residue passage, and is carried rearwardly along a generally helical path in such passage by the rotation of the rotor as grain is threshed from the crop material. The flow of crop residue or MOG remaining between the rotor and concave after threshing is typically discharged or expelled by the rotating rotor at a rear or downstream end of the rotor and the rotor residue passage in a generally downward, or a downward and sidewardly, direction in what is a continuation of the helical path of movement of the crop residue within the rotor residue passage between the rotor and concave.
The flow is typically discharged into a discharge opening at the downstream end of the rotor and into a further passage, hereinafter referred to as a discharge passage, that extends downwardly and somewhat rearwardly into a crop residue distribution system located below and rearwardly of the rear end of the threshing system. The crop residue distribution system typically includes a rotary beater or chopper or other apparatus that beats or chops the residue into smaller pieces and propels that finer crop residue rearwardly towards an area within the rear end of a combine, hereinafter referred to as a distribution chamber. The crop residue provided to the distribution chamber may be either discharged therefrom onto a field as a windrow or directed into a crop residue handling system that typically includes a chopper and spreadboard or residue spreader, hereinafter referred to generally as a chopper/spreader, mounted on or at the rear end of the combine and operable for spreading the residue over a swath of a field.
Windrowing typically occurs when, under certain conditions and in certain localities, users desire to retain the crop residue for post-processing. In such cases, the residue, which may be chopped or un-chopped, is discharged from the combine, without entering the chopper/spreader, to form a windrow directly behind the combine. Such windrow may contain only straw residue or both straw residue and chaff, and may typically be produced by moving the chopper/spreader to a position such that the residue flow will not enter the chopper/spreader or by the opening of a door at the rear of the combine. Consequently, the windrow may be formed in front of the chopper/spreader, such as when the chopper/spreader is moved out of the flow path of the crop residue from the distribution chamber, or by expulsion of the residue flow over the top of the chopper/spreader, such as when the crop residue is discharged through a rear opening from the distribution chamber.
With some combines, a chop/swath door or guide mechanism has been utilized to properly direct the crop residue from the distribution chamber. Chop/swath door mechanisms typically include a windrow door and may sometimes also have an additional deflector/kickback door associated therewith, and are employed to selectively control whether the crop residue is permitted to flow over the top of the chopper/spreader towards and through the rear opening for windrowing or is directed downwardly towards the chopper/spreader for swath spreading. When the crop residue is to be discharged through the rear opening onto a field to form a windrow on the field, the windrow door at the rear of the combine is typically caused to open and the deflector/kickback door, if one is employed, is caused to move into a position to prevent the discharge of crop flow into the chopper/spreader and to deflect the flow over the chopper/spreader towards the rear opening made accessible by the opening of the windrow door. When the crop residue is instead to be discharged into the chopper/spreader for swath spreading, the windrow door is caused to close and the deflector/kickback door, if one is employed, is caused to move to a position that permits the crop flow to be directed into the chopper/spreader. For purposes of further discussion herein, operation of a windrow door should be understood to also include corresponding operation of a deflector/kickback door if such a deflector/kickback door is employed, but the details of the corresponding operation of such a deflector/kickback door, which details are well known, will not be further specifically addressed or described herein.
When the crop residue is to be discharged onto a field to form a windrow on the field, such as through a rear opening from the distribution chamber, it is preferred that the flow being directed towards the rear opening be distributed about a center line through the rear opening to facilitate the formation of a cohesive windrow, whereas, when the crop residue is to be spread over a swath of the field, especially by a spreader having counter-rotating paddles for throwing the crop residue sidewardly in an extended swath, it is preferred that the flow being directed to the spreader be concentrated towards the center of the residue spreader for optimum spreader performance. Such dichotomy has necessarily resulted in various trade-offs in the manner in which crop residue is directed towards the rear of the combine, with the result that the flow distribution and quality is often less than is desired for either or both of the windrowing and spreading alternatives.
Several manufacturers of combine harvesters have utilized fixed convergence panels to control to some extent the trajectory and directional disposition of the flow of crop residue that is expelled or discharged from the threshing rotor and directed through the distribution chamber. Generally, such convergence panels have been installed in fixed positions to effect a convergence at the exit from the fixed convergence panels of the crop residue flow towards the centerline of the combine, which is beneficial for swath spreading by the chopper/spreader, but not for windrowing, as will be further discussed herebelow. The windrow doors of such constructions have typically been pivotable about a generally horizontal axis and operable either, in an open condition, to reveal or open the rear opening from the distribution chamber to allow the converged residue flow to exit the combine or, in a closed condition, to occlude or block the rear opening and to effect the direction of the converged residue flow towards the chopper/spreader. The problem encountered with such constructions has been that, for many applications, especially for windrowing operations and when high volumes of crop residue are being passed to the rear of the combine, the exit from such fixed convergence panels has been too small to adequately handle the crop residue flow being funneled therethrough, sometimes resulting in the formation of a plug at the exit and/or blockage of residue flow. The narrow exit that is desirable for concentrating the residue flow for introduction into the chopper/spreader for swath spreading is undesirable for windrowing, for which a wide exit would be preferred.
Accordingly, what has continued to be sought is a construction that permits a user to better and adjustably direct and control the lateral flow concentration or dispersion of the crop residue flow, depending upon whether windrowing or swath spreading of crop residue is desired, as the crop residue flow is directed for discharge as a windrow or into the spreader for spreading in a swath on the field.